.alpha. ,.beta.-unsaturated carboxylic acids and esters have the following basic formula: ##STR1## of course, with regard to the acids, R' represents hydrogen. Some of the multitude of uses for certain of these acids and esters includes monomers for the synthesis of substituted acrylic ester polymers or co-polymers. Polyacrylic acid is a useful soil conditioner. Methyl methacrylate is useful in the synthesis of polymeric thermoplastic solids and polymerizes to give a plastic called by its trade name Lucite. Many lacquers are derived from .alpha.,.beta.-unsaturated esters. Many of the compounds are useful intermediates in the synthesis of other organic compounds. Sorbic acid, an .alpha.,.beta.-unsaturated acid, inhibits the growth of fungi and molds and is useful as a food preservative. Compounds of the formula: wherein R is hydrogen or alkyl as disclosed in U.S. Pat. No. 2,859,239, are useful perfume aromatics, insecticides, herbicides, parasiticides, bactericides, and fungicides. For further information with regard to .alpha.,.beta.-unsaturated carboxylic acids and their esters and uses therefor see British Pat. No. 713,325, U.S. Pat. No. 2,807,633, French Pat. No. 952,985, British Pat. No. 668,530, U.S. Pat. No. 2,859,239, U.S. Pat. No. 2,883,418, British Pat. Nos. 779,277, 772,199, U.S. Pat. No. 2,849,466, French Pat. No. 1,413,529, U.S. Pat. No. 3,085,432, Chemical Abstracts, Vol. 76, 72151S (1972), Chemical Abstracts, Vol. 80, 23092X (1974), all of which are specifically incorporated herein by reference.
The wide range of usefulness of .alpha.,.beta.-unsaturated carboxylic acids and their esters has stimulated efforts to provide economical means of synthesis of these compounds by simple synthetic routes providing the desired compounds in high yields.
It has now been found that a direct, simple, synthetic route yielding .alpha.,.beta.-unsaturated carboxylic acids in high yields under a wide variety of reaction conditions can be achieved by utilizing vinylmercuric halides as a starting material in the reaction synthesis of .alpha.,.beta.-unsaturated carboxylic acids and esters.
Accordingly, one object of this invention is to provide a general synthetic route which has universal application for the preparation of a wide variety of .alpha.,.beta.-unsaturated carboxylic acids and esters.
Another object of this invention is to provide a synthetic method for .alpha.,.beta.-unsaturated carboxylic acids and corresponding esters which involves only a single step synthesis and avoids the utilization of high temperatures and pressures often needed in prior art synthetic routes.
Yet another object of this invention is to provide a synthetic route for .alpha.,.beta.-unsaturated carboxylic acids and esters which provides those compounds in unusually high yields when compared with prior art synthesis, generally yields in excess of 90% and often yields which are quantitative in nature.
Still another object of this invention is to provide .alpha.,.beta.-unsaturated carboxylic acids and esters by a method which utilizes vinylmercuric halides as starting materials.
The method of accomplishing these and other objects of the invention will be apparent from the description of the invention which follows.